Those Dreaded IP Addresses

Just when we thought we were done with dreaded IP addressing, Lyle resurrects the torture. Today my partner John and I completed an assignment using static addresses and various subnet masks. The skill set required was the ability to set a static address on our network adapter and a basic theoretical background on IP addresses. Sounds easy enough but add to that a laptop determined to do 468 operation updates, firewalls, Mac system software, Linux and Windows Vista, XP and Windows 7. Results did not go as expected.

My partner John and I set about to ping each other's workstations using the specified criteria and sometimes one machine would receive and the other wouldn't. OK, so we should just see if we can replicate the results. Or, we can check our results against Sean's. Now we have four different operating systems and the varied results. OK, let's use our knowledge of subnet masks to make sense of our results. John and I were OK with the standard Class A,B,C subnets but when we encountered the 255.255.252.0, it was a bit of a learning for us.

One tool we could have accessed is the online subnet calculator. This would have given us the answers about whether we could talk

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<!--[if !vml]--><!--[endif]-->The exercise did leave me wanting some more clarification on subdividing a subnet and so I spent my evening delving into the world of IP addressing. Josh Gentry's Classful Addressing site helped my understanding. This site presents the material in a very simplistic fashion. I felt that aha moment when I reached the following sentences. The subnet mask is always extended by masking off the next bit in the address, from left to right. Thus, the last octet in the subnet mask will always be one of these: 128, 192, 224, 240, 248, 252, 254 or 255.

We did find some time working on our Alcatel switches authenticating services. This proved to be a fairly simple process. The command to load these services is aaa authentication default local. To ensure that we save this authentication we needed to use the write memory command again. And, lastly, our nemesis from yesterday, copy working certified. Yes, we did learn from our mistakes!